I'd check the click adjustments on my ff3, but I really don't want to mess with my settings right now-lol. Actually, I really don't remember if they do or not.
As far as getting a Venom, I agree it's nice having more intensity settings. I also believe the Vortex has more adjustment as far as windage and elevation goes. I actually ran out of adjustment on my Burris and had to add a shim under the optic. I believe this is common with the Burris. The venom gets good reviews and I don't think I would worry about the dot drifting. Good luck.